14 BULLETIN 1072, IT. S. DEPARTMENT OF AGRICULTURE. 



has been found that Bartlett pears respire about one-half as fast at 

 30° F. as they do at 37°. The average respiration rate at 60° F. is 

 about 10 times that at 30°. It has also been found that fruit can be 

 held fully 10 times as long in storage at 30° as at 60° F. 



Fruit when held in cold storage until full yellow and soft is in- 

 variably of poor dessert quality. It is flat in taste and lacking in 

 flavor. Apparently such fruit has not developed many of the com- 

 pounds that give it the peculiar odor and flavor found in fruit that 

 has not been held in storage at low temperatures. In the case of 

 Bartlett pears, however, it has been found that fruit may be held in 

 storage for periods up to two to three months and then taken out 

 while still hard and green, provided it has been held in temperatures 

 of 28° to 30° F. Such fruit should be ripened at a temperature of 

 60° to 70° F., and when removed from storage it will develop much 

 of the aroma and flavor found in pears that have ripened in normal 

 temperatures. Invariably it has been found that pears handled in 

 this way, by storing at the minimum temperature until the fruit is to 

 be used and then removing from storage entirely and ripening it at 

 temperatures of 60° to 70° F., have given a product of higher dessert 

 quality than that obtained by any other storage method. This 

 method of handling is to be recommended, regardless of whether the 

 fruit is intended for canning or for a late fresh-fruit market follow- 

 ing removal from storage. 



There has been some criticism among cannery men of holding pears 

 at so low a temperature. It has even been said that such a procedure 

 will cause the pears to discolor in the can. In order to determine 

 whether or not a season at low temperature injures the fruit for can- 

 ning, a quantity of pears from two different orchards was removed 

 from storage on December 29, 1920, and was canned on January 4, 

 1921, almost five months after picking. This fruit made a canned 

 product of very good quality and of splendid appearance, though 

 there was considerable waste in preparing the pears for canning 

 after so long a season in storage. This practice is not to be recom- 

 mended, nor is it desirable from the canners' viewpoint that pears 

 for the cannery be held more than two months in storage. The fact, 

 however, that this fruit after so long a storage season still made an 

 excellent canned product entirely refutes the theory that cold-storage 

 pears, particularly if held at low temperatures during storage, make 

 a poor quality of canned fruit. 



Another important matter to the canner is the fact that pears from 

 the districts producing fruit of poor keeping quality, such as those 

 along the California coast, can be handled safely through cold stor- 

 age. During the summer of 1920 a large quantity of pears from 

 Santa Cruz County, Calif., supposed to be among the poorest keep- 

 ing Bartletts in the State, was put in storage under the observation of 

 the writer. This fruit was held at 30° to 31° F. for more than a 



